1. Field of the Invention
This invention relates to a device for moving a stage on a surface, and more particularly to a device for sliding a stage slidable on a flat or cylindrical surface.
2. Description of the Prior Art
A device for moving or sliding a stage on a two-dimensional surface is widely used in various fields like a microfilm recording apparatus, an inspection device for IC elements, a plotter for a drafting machine and the like. In such a stage moving device, it is desired that the stage be moved at a high speed and the stage be settled at a desired position with high accuracy and with a short settling time.
In a computer output microfilmer (COM) for recording a computer output on a microfilm, for instance, it is required that the stage which holds a microfilm be moved to a desired position at a high speed and with high accuracy and then be moved to the next position quickly to successively record the information at a very high speed. In order for the COM to record the information on the microfilm immediately after the film is stopped, the vibration of the stage must be quickly stopped after the stage is stopped at the desired position. In other words, the settling time from the stoppage of the driving source like a motor used for moving the stage up to the desired position to the complete stoppage of the vibration of the stage is desired to be as short as possible. In the conventional devices, however, the settling time is not short enough to provide a practically satisfactory high speed COM. It should be noted here that the vibration of the stage may not be perfectly stopped for the information to be recorded on the microfilm, but may be substantially stopped or damped to a negligible level.
As the conventional X-Y moving devices are known, for example, those as shown in Japanese Patent Publication No. 49(1974)-14266, Japanese Patent Publication (first publn.) No. 48(1973)-63722, Japanese Patent Publication (first publn.) No. 53(1978)-3816, Japanese Utility Model Publication (first publn.) No. 53(1978)-6640 and Japanese Utility Model Publication (first publn.) No. 53(1978)-6641. The X-Y moving devices as shown in these publications are all used for a microfilm camera and employs electric motors for driving the mechanism in X- and Y-directions respectively. Many of these devices have one mechanism for moving the stage in one direction (e.g. Y-direction) on the other mechanism for moving the stage in the other direction (e.g. X-direction). In such a mechanism, the motor used for moving the stage in X-direction needs a large torque. Further, in order to transmit a driving power to the mechanism for moving the stage in Y-direction, it is necessary to put the motor for moving the stage in Y-direction on the mechanism for moving the same in X-direction or to transmit the power by way of a spline or the like. Thus, in the above-described devices for moving the stage on a two-dimensional surface, a motor of large torque or a complex mechanism for transmitting power is necessitated, and further it is difficult to make the size of the device compact.